Pretty quick. I went through two on-campus interviews. The interviewers were friendly and did not try to intimidate you. I did not think I did very well, but I still received an offer by the end of the week. From what I gathered, they do not have very high standards for hiring interns, but when it comes to extending an offer at the end of the internship, they prune aggressively.

Some string manipulation in Java. You have to know how to use StringBuffer's fairly well. Also, tree/graph related questions were asked a lot.